This invention relates to apparatus for generation of an electrical code representative of a commodity identification for label printing apparatus or the like. Such apparatus find particular utility in combination with an automatic weighing and labeling system of a type commonly employed in large volume supermarket packaging operation. A typical system in which the present invention may be employed may be of a type as generally described in Allen U.S. Pat. No. 2,948,465. Such systems comprise a scale for weighing a commodity, such as a package of meat, a register for storing the weight of the commodity as measured by the scale, means for entering the price per pound of the commodity being weighed, means for multiplying the weight times the price per pound to obtain a total value for the commodity, and means for printing the total value, together with other appropriate information, on a label for application to the package.
Packages which have been labelled as above described are commonly placed on counters for selection by a customer, who in turn transports the selected package to a checkout station. At the checkout station a clerk reads the value printed on the package label and manually enters this value into a cash register for totalling up the customer's bill. In recent times, there has been keen interest in printing machine readable codes on such labels, so as to speed up the checkout process. Accordingly there have been developed a number of machine readable codes, the most common of which are bar codes, which may be ready by a photosensitive hand held wand or a photosensitive device mounted within the surface across which the coded package is passed.
The bar codes currently coming into use identify the manufacturer of the product and also provide a specific identification of type and size of the product. Such an identification code enables setting up of an automatic inventory control program by a computer to which the photosensitive code reading device may be attached. Furthermore, for packages of standard size, the price of the package may be stored in memory, so that the computer can provide automatic control of the operation of the cash regisiter. The bar codes for such "standard" items are preprinted on the package by the manufacturer prior to delivery to the retailer.
In the case of locally packaged products, such as produce and meat, which are sold by weight, it is necessary for the retailer to print his own machine readable label. Furthermore it is desirable that the printer for printing such machine readable labels be compatible with available computing scale systems, so that it is possible to print a machine readable code corresponding to weight or package value in addition to a product identification code. Thus the reading system will have all the information necessary for inventory control and/or automatic cash register operation.
In accordance with this invention it is proposed to provide a commodity key which conditions the labeling system for operation and which carries a machine readable code representative of the identity of a commodity being processed. Such a commodity key may also carry a type face for printing the name of the commodity in ordinary language on the label. The above mentioned Allen patent discloses a commodity key having means for conditioning the labeling system for operation and a type face for printing the name of the commodity on the label. The labels which are printed by the Allen system, however, do not carry a machine readable code.
Other prior art systems which disclose usage of commodity keys are Bell RE25,897, Bremner 3,789,193, Susor 3,459,272 and Martin 3,825,085. The commodity keys shown in each of these latter three patents carry machine readable indicia, but in each case the machine readable indicia represents the price of the commodity and does not identify the commodity itself. In the Bell patent the machine readable indicia are a series of pins which position a series of selector switches when the key is slid into place. The key of the Martin patent is similar to the Susor key, but there is provision for a parity check.
In the Bremner, Susor and Martin patents the machine readable indicia are a series of apertures for passage of light from a suitably positioned light source. Light which passes through these apertures is sensed by a series of photodiodes, which in turn cause production of a signal code representative of a commodity price. In the Susor and Martin patents, the key contains a series of apertures which are blocked on a selective basis by masks which are attached to the key. Reading of the light passing through the apertures is done with the key in place. In the Bremner patent, the key carries a series of tabs, each of which has a row of apertures representative of a price digit. Each tab also has a second row of apertures for generation of clock pulses. As the key is slid into place one photodiode senses the row of clock apertures in each of the tabs, thereby generating a clocking signal which controls the reading and storage of the price digit information.
Other U.S. Pat. Nos., Susor et al 3,459,271 and Bell 3,291,232 disclose a commodity key or plate carrying machine readable indicia, which are pins of the same general type shown in Bell RE25,897. In Susor et al U.S. Pat. Nos. 3,459,271 and Bell 3,291,232, however, the pin locations represent a commodity identification, rather than a price. The commodity price identification as indicated by these pins is transmitted to a centralized computer in which up-to-date price information is stored. The central computer transmits back to the computing weighing scale system, with which the key is associated, the price for the commodity being processed. None of the above mentioned references is concerned with the printing of machine readable codes for package labels.